The trend in modern housing developments has been to run all utility service, including telephone lines, underground. Each phone line installation requires a line pair from the house out to a multi-line cable running along the property lines of the houses where a junction is required to tie the line pair into the cable. Some type of water-tight and air-tight junction box must be provided to allow a splicer to tie the service line from the house into the multi-line cable. If a customer at any time requires an additional line, the junction box must be opened up and a new service line spliced into the cable. This splicing operation has proven to be a source of trouble, resulting in higher installation and maintenance costs. Trouble may result either from the junction box not being properly sealed so that moisture is later able to enter or the splicing operation is not properly carried out.
Generally, the companies have hired trained personnel, called splicers, who handle the connection of service lines into a main multi-line cable, whereas, less highly trained personnel, referred to as installers, are used to install phone equipment at the subscriber's premises. In the past, equipment for connecting underground lines into an underground cable has required the skill of the splicer to be employed whenever additional service lines were to be added to the system.